thigh banging 

The act of a man penetrating their partner from behind, and not realizing that their penis has come out of the perspective hole. Thus they continue to penetrate the thighs. This usually occurs when the man is drunk and/or high.

We drank a fifth of vodka and smoked a few bowls, then had sex. We ended up getting thigh banging, because he didn't realize his penis came out.

thigh banging by PartyOn May 9, 2014